The gap adjusting mechanism of air-pressure disc brake
Technical field
The present invention relates to a kind of disk type braker of pneumatic control, especially relate to a kind of gap adjusting mechanism.
Background technique
The disk type braker of pneumatic control is applied in urban public traffic vehicles, medium-to-high grade sightseeing bus, heavily loaded goods carrying vehicle now more and more.
The type disk type braker is comprised of unsteady caliper, bracket, brake slipper, brake disc.The caliper that wherein floats consists of brake lever, hold down gag, Returnning spring, gap adjusting mechanism.The major function of gap adjusting mechanism is the wearing and tearing of compensation brake slipper in braking process, guarantee that the air gap between brake slipper and brake disc is constant, at disk type braker, be on active service the stage, air gap value should not depend on the state of wear of brake slipper and polishing machine and keep constant.
Because the gap adjusting mechanism of pneumatic control disk type braker can only make gap excessive between brake slipper and brake disc reduce, and can not increase the gap between brake slipper and brake disc, so clearance adjustment mechanism should possess unidirectional regulatory function.And in order to eliminate excessive braking force, gap adjusting mechanism must have torque overload protective function, overload protection function is normally realized by overload clutch.The unidirectional adjustment function of gap adjusting mechanism of prior art mainly realizes by helical torsional spring, this structure has proposed very high requirement to the performance of helical torsional spring, and domestic material and technique are difficult to bonding to stability and the reliability of adjusting function.The overload protection function of the gap adjusting mechanism of prior art is realized by multiplate clutch sheet, and this complicated structure is high to material requirements, and then has increased cost.
Summary of the invention
The object of the present invention is to provide a kind of gap adjusting mechanism of air-pressure disc brake of simple in structure, reliable performance.
In order to achieve the above object, technological scheme of the present invention is: a kind of gap adjusting mechanism of air-pressure disc brake, comprise shift fork, flange, ball, overload clutch, adjusting axle and fixed tray, described fixed tray and flange are rotatably assorted and are sleeved on adjusting axle, described shift fork is enclosed within outside flange, described overload clutch is positioned at the bottom of adjusting axle, described overload clutch comprises housing, spring and fast pulley, one end and the inner walls of spring offset, the other end and fast pulley offset, fast pulley is fixed on the bottom of adjusting axle, the periphery of described housing is provided with external splines, described flange has Step Shaft and flange plate, Step Shaft is upper, flange plate under, the endoporus of described shift fork coordinates with the outer ring of a unidirectional needle bearing, the inner ring of unidirectional needle bearing is arranged on the Step Shaft of flange, the lower end surface of the flange plate of described flange has several the first pits, the upper-end surface of the housing of described overload clutch has several second pits corresponding with the first pit of flange, described ball is contained in the cavity volume forming between the first pit and corresponding the second pit, the inwall of the housing of described overload clutch has spline, the periphery of fast pulley has spline tooth, spline tooth coordinates with spline, between described fixed tray and shift fork, be provided with tension spring, described flange is provided with back-up ring, back-up ring gear is in one end of unidirectional needle bearing and one end of Step Shaft, between the boss of described adjusting axle and fixed tray, wear plate is installed.
The lower end of described adjusting axle has flat gesture, and adjusting axle is riveted together by the endoporus of flat gesture and fixed block.
The upper end of described Step Shaft has counterbore, and described back-up ring is the sleeve with flanging, and the flanging part of back-up ring offsets with the upper end of unidirectional needle bearing, and counterbore bottom is stretched in the sleeve part of back-up ring.
Adopt after said structure, the present invention is when between brake slipper and brake disc during excesssive gap, and in braking state, actuating mechanism brake lever is actuated the fixedly contact pin of shift fork, drives shift fork to rotate; Due to the effect of unidirectional needle bearing, shift fork and flange are locked, and flange rotates under the drive of shift fork; At rotation torque, do not have when excessive, flange drives clutch housing to rotate together by ball; The threaded pipe rotation that rotarily drives disk type braker of clutch housing, thus gap eliminated.After braking is cancelled, actuating mechanism brake lever drives shift fork counterrotating, and now unidirectional needle bearing allows to relatively rotate between shift fork and flange, so flange does not rotate, clutch housing does not have counterrotating, and therefore the gap in original excessive gap is eliminated.The present invention adopts unidirectional needle bearing to replace the helical torsional spring of prior art, and therefore, simple in structure, stability and reliability are high.
Accompanying drawing explanation
The present invention is further detailed explanation for the embodiment who provides below in conjunction with accompanying drawing.
Fig. 1 is the structural representation of the gap adjusting mechanism of air-pressure disc brake of the present invention;
Fig. 2 is the perspective view of the shift fork of Fig. 1;
Fig. 3 is the B portion partial enlarged drawing of Fig. 1;
Fig. 4 is the A-A sectional view of Fig. 1.
Embodiment
As shown in Fig. 1 ~ 4, a kind of gap adjusting mechanism of air-pressure disc brake, comprise shift fork 1, flange 3, ball 4, overload clutch 5, adjusting axle 7 and fixed tray 8, described fixed tray 8 and flange 3 are rotatably assorted and are sleeved on adjusting axle 7, described shift fork 1 is enclosed within outside flange 3, described overload clutch 5 is positioned at the bottom of adjusting axle 7, described overload clutch 5 comprises housing 5-1, spring 5-2 and fast pulley 6, one end of spring 5-2 and housing 5-1 inwall offset, the other end and fast pulley 6 offset, fast pulley 6 is fixed on the bottom of adjusting axle 7, the periphery of described housing 5-1 is provided with external splines 5-1-1, described flange 3 has Step Shaft 3-1 and flange plate 3-2, Step Shaft 3-1 is upper, flange plate 3-2 under, the endoporus of described shift fork 1 coordinates with the outer ring of a unidirectional needle bearing 2, the inner ring of unidirectional needle bearing 2 is arranged on the Step Shaft 3-1 of flange 3, the lower end surface of the flange plate 3-2 of described flange 3 has several first pits 3-2-1, the upper-end surface of the housing 5-1 of described overload clutch 5 has several second pit 5-1-1s corresponding with the first pit 3-2-1 of flange 3, described ball 4 is contained in the cavity volume forming between the first pit 3-2-1 and corresponding the second pit 5-1-1, the inwall of the housing 5-1 of described overload clutch 5 has spline 5-3, the periphery of fast pulley 6 has spline tooth 6-1, spline tooth 6-1 coordinates with spline 5-3, between described fixed tray 8 and shift fork 1, be provided with tension spring 10, described flange 3 is provided with back-up ring 11, back-up ring 11 gears are in one end of unidirectional needle bearing 2 and one end of Step Shaft 3-1, between the boss 7-1 of described adjusting axle 7 and fixed tray 8, wear plate 9 is installed.
Described the first pit 3-2-1, the second pit 5-1-1 and ball 4 quantity equate, have a ball 4 in each cavity volume.
As shown in Fig. 1,4, the lower end of described adjusting axle 7 has flat gesture 7-2, and adjusting axle 7 is riveted together by the endoporus 6-2 of flat gesture 7-2 and fixed block 6.
As shown in Figure 1, the upper end of described Step Shaft 3-1 has counterbore 3-1-1, and described back-up ring 11 is the sleeve with flanging, and the flanging part of back-up ring 11 offsets with the upper end of unidirectional needle bearing 2, and counterbore 3-1-1 bottom is stretched in the sleeve part of back-up ring 11.
As shown in Fig. 1 ~ 4, when the present invention uses, at air-pressure disc brake normal brake application state, when the air gap between brake slipper and brake disc surpasses setting air gap value, from the fixedly contact pin 1-1 rotation that rotarily drives shift fork 1 of Disk Brake lever, and then drive shift fork 1 rotation; In braking state, unidirectional needle bearing 2 is in locking state, and the rotation of shift fork 1 drives flange 3 to rotate by unidirectional needle bearing 2.
If transmit from flange 3 rotation torque coming, do not surpass the Maximum Torque that overload protective device sets, flange 3 will drive overload clutch housing 5-1 to be rotated by ball 4; Clutch housing 5-1 inside has some spline 5-3, the outer ring of fixed block 6 has some spline tooth 6-1, coordinate transmitting torque with the spline 5-3 of clutch housing 5, endoporus 6-2 and the adjusting axle 7 of fixed block 6 are riveted together, the rotation of clutch housing 5-1 is delivered on adjusting axle 7 by the endoporus 6-2 of spline 5-3, external splines 5-1-1, fixed block 6, and adjusting axle 7 is synchronously rotated with clutch housing 5-1; Between adjusting axle 7 and fixed tray 8, there is antifriction sheet 9, allow adjusting axle 7 with respect to fixed tray 8 rotations.The outside of clutch housing 5-1 has external splines 5-1-1, and external splines 5-1-1 drives the screw rod of disk type braker to be rotated, and the rotation of screw rod is converted into axial displacement, has eliminated the gap between brake slipper and brake disc.
After the gap between brake slipper and brake disc is eliminated; brake slipper is pressed close to brake disc; rotation torque from shift fork 1 and flange 3 can increase suddenly so; when moment of torsion surpasses the Maximum Torque that overload protective device sets; all balls 4 are moving to adjacent another to pit 3-2-1,5-1-1 from a pair of pit 3-2-1,5-1-1; eliminated the rotation torque from flange 3, clutch housing 5-1 will no longer rotate with flange 3 jointly so.
During release of brake, between brake slipper and brake disc, produce air gap, when air gap just will surpass setting air gap, brake lever drives the fixedly contact pin 1-1 opposite spin of shift fork 1, and then drive shift fork 1 opposite spin, now unidirectional needle bearing 2 is in releasing orientation, and flange 3 can not be followed shift fork 1 counterrotating together, and clutch housing 5-1 can not be rotated yet.Therefore the air gap being eliminated in braking state can't regenerate, thereby has played the effect of compensate for clearance.